Ore pulp concentrator



Get. 13, 1953 c s o 2,655,263

ORE PULP CONCENTRATOR Filed Oct. 12, 1950 Patented Oct. 13, 1953 ORE PULP CONCENTRATOR Gilbert. G. Chisholm, Lucan, Ontario, Canada, assignor to Fcrros Metals Research Company Limited, Toronto, Ontario, Canada Application October 12, 1950', Serial No. 189,867

This invention relates to a concentrator device for ore pulp.

It is well known that heretofore there has been no practical method for saving iron values from the ore of the Mesabi Range from material finer than 100 mesh.

It is the particular object of this invention to provide an ore pulp concentrating device particularly adaptable to concentrating the fines of an ore and particularly to the obtaining of iron values in a practical manner from'slime tailings or waste of washing plants, and especially those plants which use Mesabi ores.

Having regard to this and other objects, the

invention generally comprises an ore pulp concentrator in the form of a pair of opposed coaxial cone members diverging toward one another to be joined by a collar portion. The common axis of the cones is disposed vertically, said collar having an inlet nozzle designed to direct pulp under pressure substantially tangentially to the inner surfaces of the collar. The pulp is caused to swirl within the structure, those particles of greater specific gravity falling through a concentrate nozzle forming the outlet opening at the apex of the lower cone member. Due to the circulation of the pulp within the concentrator a vortex is set up about the axis of the cones having a minimum diameter determined by the concentrate nozzle, A pulp return collar extends inwardly from the Walls of the upper or tailings cone to form a tailings opening of a diameter greater than the diameter of the concentrate nozzle and greater than the apex opening of the upper tailings cone. A surge pipe extends upwardly from the apex opening and a tailings pipe leads at right angles therefrom. In its action, the lighter media are caught by the circulation on the edges of the vortex and drawn upwardly but inwardly of the pulp return collar toward the surge pipe and tailings pipe for discharge. The concentrate nozzle in its formation allows air at normal pressure to flow upwardly along the axis of the concentrator to thereby more effectively control the form of the vortex formed by the circulation of the pulp within the concentrator.

Other objects of the invention will be appreciated by a study of the following specification taken in conjunction with the accompanying drawings.

In the drawings:

Figure 1 is a sectional view along the axis of a concentrator according to the invention.

Figure 2 is a reduced scale sectional view of 1 Claim. (01. 209-211) 2 the concentrator of Figure 1 on th line 2-2 thereof.

A concentrator according to the invention is comprised of the sheet metal body In formed of a tailings cone H and a concentrate cone l2 supported co-axially by a collar member I3. An inlet nozzle I l joins to the collar I3 as at I5 to cause injection of pulp under pressure in the direction of the arrow Y illustrated in Figure 2, that is, tangentially or on a curve parallel to the inner surfaces of the collar l3.

In one preferred form which it is desired, without limitation, to illustrate in detail, the diameter of the collar i3 may be about twelve inches and the concentrate cone converges therefrom downwardly at an angle of about 30 to the horizontal to an apex opening it of about two inches in diameter. From this point a concentrate nozzle I! in the form of a small frustro cone depends with its side walls at an angle of about 78 to the horizontal to form a nozzle opening 18. The tailings cone ll converges at an angle of about 38 to the horizontal in the upward direction to a tailings cone opening [9 about which a surge pipe 20 is fastened to extend upwardly. The opening l9 may be about four inches. A suitable tailings pipe 2| extends at right angles from the surge pipe 20.

In operation, the pulp is introduced on the path Y illustrated in Figure 2 and forms a vortex 22 indicated by chain lines in the form of an air column rising from the concentrate nozzle through to the surge pipe. The circulation of particles on an axial section of the device is illustrated in Figure 1, wherein the circulation of the heavier media is illustrated in bold arrows and the circulation of the light media or tailings illustrated by arrows in chain lines. The action of the device is to cause centrifugal force to throw the heavier media to the outside and allow the lighter particles to be forced to the inner section of the device where they come in contact with the very powerful vortex 22 at the point 23 and are carried up the vortex in a spiralling path 24 into the surge pipe 20 to be thrown into and discharged from the tailings pipe 2|.

The separating action is more carefully controlled by means of a pulp return collar 25 mounted on the tailings cone II below the tailings opening [9 thereof and projecting inwardly from the side walls of the tailing cone in the form of an inwardly directed annular flange 26, the terminal edge 21 of which is of a diameter greater than the diameter of the opening l9 and of about four and one-half inches having regard to the operations of other dimensions specified herein. The pulp return collar functions to cut away entrained heavy media which may be passing upwardly or circulating upwardly with the material on the margins of the vortex. In particular it will be observed that the diameter of the opening defined by the inwardly directed edge 21 of the pulp return collar must in all cases be greater than the diameter of the vortex formed. It should also be observed that the tailings cone is of a lesser degree of convergence than. the concentrate cone to facilitate the rise of ore pulp within the tailings cone and to enable the use of a lower pressure in the injection of pulp for initiating and maintaining the vortex action. This results in a looser pulp mass, thusvexpediting separation of the heavy particles from the light ones.

Extensive tests have been run with devices fabricated in accordance with theim'inclples'onte lined herein on very fine iron ore tailingsirom the washing plants of the Mesabi Iron Range. All of these tests have been made without the use of heavy media or, that is, on. material of which greater than 70% is finer than minus 100 mesh. Recovery on material of this type has resulted in obtaining over 80% of the content iron values,

It is intended that the present disclosure should not be construed in any limiting sense having regard to. the specific dimensionsillustrated herein for a workable and practicaldevice according to the invention. Accordingly, the following claim is set forth to define the intended scope of the invention.

What I claim as my-invention is:

An ore pulp concentrator adapted to form a substantially unrestrained fluid vortex with the ore pulp injected therein-to and comprising, in

combination: a cylindrical collar member; a pulp injector nozzle mounted tangentially on the said collar member and adapted to direct an ore pulp tangentially into the interior thereof; a tailings cone and a concentrate cone having a common axis and extending respectively from said collar member to define a tailings opening of predetermined diameter and a concentrate opening of substantially lesser diameter; a tailings outlet pipe mounted exterior of and adjacent to said tailings opening and extending substantially at right angle from said common axis; and a surge pipe of a diameter corresponding to the diameter of said tailings opening communicating between the latter and said tailings outlet pipe, co-axial with said cones and extending beyond said tailings outlet pipe to serve efiectively as a continuation of said tailings opening substantially nonrestrlctive to a vortex formed in the concentrator between the concentrate opening and the tailings opening thereof.

GILBERT G. CHISHOLM.

References Cited. in the file of this patent UNTI'ED STATES PATENTS Number Name Date 762,866 Allen June M, 1904 1,91,653 Hill July 25, 1933 2,236,548 Prouty Apr. 1, 1941 2,273,271 Kerns Feb. 17,. 1942 2,330,423 Hart Sept. 28, 1943 FOREKGN PATENTS Number Country Date 340,02? Great Britain Dec. 19, 1930 607377 Great Britain Sept. 6, 1M8

OTHER REFERENCES.

Colliery Engineering #319, vol. 2'2, pages 348- Sept. 1950'. 

